Handheld Devices and Methods for Extracting Data

ABSTRACT

The present invention relates generally to handheld devices and using such to extract identifying data. One claim recites a handheld wireless device including: an input for receiving a subset of database information; electronic memory for storing the retrieved subset of database information, the handheld device including an input device; an optical imaging device for capturing a portion of a map, the portion of the map including at least one steganographic watermark hidden therein through alterations to data representing the portion, the alterations being generally imperceptible to a human observer of the portion of the map, the steganographic watermark including map location information; an electronic processor configured to: determine which information of the retrieved subset of the database information corresponds to the map location information; and control providing corresponding retrieved subset database information. Other claims and combinations are provided as well.

RELATED APPLICATION DATA

This application is a continuation of U.S. patent application Ser. No.11/781,677, filed Jul. 23, 2007 (U.S. Pat. No. 7,506,169), which is acontinuation of U.S. patent application Ser. No. 09/833,013, filed Apr.10, 2001 (U.S. Pat. No. 7,249,257). Each of the above patent documentsis hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to handheld devices, navigation and/or maporientation, and in some cases is illustrated with reference to maps andsigns embedded with digital watermarks.

BACKGROUND AND SUMMARY OF THE INVENTION

A map is both a beloved and bewildering companion to those who choose tonavigate an unfamiliar city or traverse across country to find ablissful vacation spot. Map navigation becomes even more difficult forthose who retreat into the wilderness, some becoming lost, unable totraverse the unfamiliar terrain with a map.

Countless children, stuffed into the backseats of vacation-bound stationwagons, sport utility vehicles and Volkswagen bugs, have pleaded to knowif “we are there yet.” Befuddled parents search for convincing answersas they unfold yet another map.

In some circles, orienteering and adventure racing rise to the level ofcompetition, drawing crowds of participants and network audiences. Suchcompetitions force participants to navigate through mountains, streams,and deserts, often guided only by a compass and map.

Many young geography students, when presented with a world or area map,struggle to accurately place themselves within a map to determine theirrelationship to various area or world locations.

Commercial and recreational boats and aircraft often travel throughunfamiliar areas and must skillfully navigate in order to reach theirintended destinations.

Global positioning systems (GPS) have improved navigation by providingaccurate location feedback. As will be appreciated by those skilled inthe art, military and civilian water, ground, and airborne vehiclesoften use GPS systems for navigation. GPS is a satellite-based radionavigation system capable of providing continuous position, velocity,and time information. GPS receiver units receive positioning signalsfrom a constellation of satellites deployed in various orbits aboutearth (e.g., 12-hour orbits). The satellites continuously emitelectronic GPS signals (or telemetry) for reception by ground, airborne,or watercraft receiver units. By receiving GPS signals from a pluralityof satellites, a properly configured receiver unit can accuratelydetermine its position in three dimensions (e.g., longitude, latitude,and altitude).

There are many known GPS systems. For example, U.S. Pat. No. 5,990,826discloses an interbuilding and urban canyon extension solution forglobal positioning systems.

U.S. Pat. No. 5,861,841 discloses a compact GPS receiver/processor. TheGPS system including an antenna to receive Global Positioning System(GPS) signals from two or more GPS satellites and a credit card size GPSsignal processing Smartcard. The Smartcard is attached to the antennathat receives the GPS signals and determines and displays the presentposition of the antenna.

U.S. Pat. No. 5,964,821 discloses a navigation system for offeringnavigational assistance to a mobile user. The navigation system receivesGPS position information signals, which are processed to determinecurrent position latitude and longitude coordinates and direction oftravel.

Of course, there are many other GPS systems known to those of ordinaryskill in the art.

Some embodiments employ digital watermarking techniques to even furtherease navigation and map orientation. In some embodiments, digitalwatermarking techniques are combined with GPS systems. Applications ofthe present invention include implementations in fields such asgovernment work and field reconnaissance, commercial or recreationalboating, hiking, mountaineering, travel, orienteering, geography,education, exploration, entertainment, sight seeing, etc.

Digital watermarking, a form of steganography, is the science ofencoding physical and electronic objects with plural-bit digital data,in such a manner that the data is essentially hidden from humanperception, yet can be recovered by computer analysis. In physicalobjects, the data may be encoded in the form of surface texturing, orprinting. Such marking can be detected from optical scan data, e.g.,from a scanner, optical reader, input device, digital camera, or webcam. In electronic objects (e.g., digital audio or imagery—includingvideo), the data may be encoded as slight variations in sample values.Or, if the object is represented in a so-called orthogonal domain (alsotermed “non-perceptual,” e.g., MPEG, DCT, wavelet, etc.), the data maybe encoded as slight variations in quantization values or levels. Theassignee's U.S. Pat. No. 6,122,403 and U.S. application Ser. No.09/503,881 (now U.S. Pat. No. 6,614,914) are illustrative of certainwatermarking technologies.

Digital watermarking systems typically have two primary components: anencoder that embeds the watermark in a host media signal, and a decoderthat detects and reads the embedded watermark from a signal suspected ofcontaining a watermark (e.g., a suspect signal). The encoder embeds awatermark by altering the host media signal. The decoder componentanalyzes a suspect signal to detect whether a watermark is present. Inapplications where the watermark encodes information, the decoderextracts this information from the detected watermark.

The analysis of the detected data can be accomplished in various knownways. Presently, most steganographic decoding relies on general purposemicroprocessors that are programmed by suitable software instructions toperform the necessary analysis. Other arrangements, such as usingdedicated hardware, reprogrammable gate arrays, or other techniques, canof course be used.

Determining orientation of embedded data can be discerned by referenceto visual clues. For example, some objects include subliminal graticuledata, or other calibration data, steganographically encoded with theembedded data to aid in determining orientation. Others objects canemploy overt markings, either placed for that sole purpose (e.g.reference lines or fiducials), or serving another purpose as well (e.g.lines of text), to discern orientation. Edge-detection algorithms canalso be employed to deduce the orientation of the object by reference toits edges.

In one example, subliminal graticule data can be sensed to identify thelocations within the image data where the binary data is encoded. Thenominal luminance of each patch before encoding (e.g., backgroundshading on a map) is slightly increased or decreased to encode a binary“1” or “0.” The change is slight enough to be generally imperceptible tohuman observers, yet statistically detectable from the image data.Preferably, the degree of change is adapted to the character of theunderlying image, with relatively greater changes being made in regionswhere the human eye is less likely to notice them. Each area thusencoded can convey plural bits of data (e.g., 16-256 bits).

One problem that arises in many watermarking applications is that ofobject or positioning corruption. If the object is reproduced, skewed,or distorted, in some manner such that the content presented forwatermark decoding is not identical to the object as originallywatermarked, then the decoding process may be unable to recognize anddecode the watermark. To deal with such problems, the watermark canconvey a reference signal. The reference signal is of such a characteras to permit its detection even in the presence of relatively severedistortion. Once found, the attributes of the distorted reference signalcan be used to quantify the content's distortion. Watermark decoding canthen proceed—informed by information about the particular distortionpresent.

The assignee's U.S. application Ser. Nos. 09/503,881 (now U.S. Pat. No.6,614,914) and 09/452,023 (now U.S. Pat. No. 6,408,082) detail certainreference signals, and processing methods, that permit such watermarkdecoding even in the presence of distortion. In some image watermarkingembodiments, the reference signal comprises a constellation ofquasi-impulse functions in the Fourier magnitude domain, each withpseudorandom phase. To detect and quantify the distortion, the watermarkdecoder converts the watermarked image to the Fourier magnitude domainand then performs a log polar resampling of the Fourier magnitude image.A generalized matched filter correlates the known orientation signalwith the re-sampled watermarked signal to find the rotation and scaleparameters providing the highest correlation. The watermark decoderperforms additional correlation operations between the phase informationof the known orientation signal and the watermarked signal to determinetranslation parameters, which identify the origin of the watermarkmessage signal. Having determined the rotation, scale and translation ofthe watermark signal, the reader then adjusts the image data tocompensate for this distortion, and extracts the watermark messagesignal as described above.

Such watermarking techniques, and many others known to those skilled inthe art, may be suitably employed to improve navigation, easy roadjourneys and enhance education, among other benefits.

The foregoing and other features and advantages will be more readilyapparent from the following detailed description, which proceeds withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a map, which is divided into blocks.

FIG. 2 illustrates various components of a watermark reading device.

FIG. 3 illustrates the device of FIG. 2 in relation to the map of FIG.1.

FIG. 4 is a flow diagram illustrating a method according an embodiment.

DETAILED DESCRIPTION Watermark Embedding

In accordance with a first embodiment, a map 10 includes plural-bit datasteganographically encoded therein. (The term map is used broadly hereinand includes, for example, navigational tools and documents, road maps,atlases, wilderness maps, area maps, city maps, tourist maps, locationguides, walk or run routes, path-layouts, 3-demesional models,vegetation maps, building maps, structure maps, stadium seating andconcert hall locations, park maps, amusement or theme park maps, DEMmaps, master maps, topographical maps, globes, relief maps, to name justa few. A map may also include a digitized map for display on a monitor,TV, LCD, etc.). Map 10 can be printed or drawn on any suitable surfaceincluding paper, fibers, fabric, wood, plastic, metal, metal-alloys,objects, plaster, laminates, etc., etc. A digitized map image mayinclude plural-bit data steganographically encoded therein.

The encoding of the map can encompass artwork or printing on the map,the map's background, lines on the maps, a laminate layer applied to themap, surface texture, etc. If a photograph, line design, or drawing ispresent, it too can be encoded. A variety of watermark encodingtechniques are detailed in the patent documents discussed herein;artisans in the field know many more.

Preferably, map 10 is embedded with a plurality of watermarks. As shownin FIG. 1, map 10 is divided into a plurality of areas A-P (e.g.,blocks, patches, or segments, etc.). Of course, the number of blocks orareas can be varied, with enhanced precision resulting from an increasednumber of blocks. Each area is preferably embedded with at least onewatermark. (In one embodiment, each individual block is redundantlyembedded with multiple copies of a respective unique watermark—furtherenhancing the robustness of the map. In another embodiment, some of theblocks are subdivided, with at least one unique watermark embedded ineach subdivision.).

A watermark typically includes a payload (e.g., 16-256 bits) thatprovides area (or location) identifying information. For example, thepayload may include the geo-coordinates (e.g., “center lat: N34.4324352,long: W87.2883134; rot from N/S: 3.232; x2.343, y2.340, dx0.123, dy493,etc.”) for the center of the area, the coordinates of each area corneror boundary, the area of the boundary, a range of coordinates for thearea, coordinates in relation to the overall area depicted by the map,and/or the coordinates for a dominate (or well-known) structure, road,area, etc., within the area block. (For example, area A is embedded withat least one watermark having coordinates corresponding to area A'scenter or corners, etc.). The payload may simply be a number that isassociated with a block location on the map. For example, if a mapcomprises 32 by 64 watermarked blocks, each block is encoded with anumber between 1 and 2048.

Further, the payload may include additional fields, one conveying a mapID and another conveying the block number. The map ID may be used toidentify the map as one of a collection of potentially many differentmaps. To program a map reader (as discussed below) for a particular mapin the collection, the user passes the reader over the map to read themap ID (or simply enters the map ID). The reading device is thenconnected to a database, via a docking station at a personal computer orthrough a wireless connection. The reading device queries the databasewith the map ID and the database returns information associated withitems of interest on the particular map (such as restaurants, scenicareas, camp sites, etc.) The user then disconnects the reader from thedatabase and is ready to use the map.

In another embodiment, some bits in the watermark payload identify thelatitude/longitude of the map origin, while other payload bits identifythe coverage extent of the map. Additional payload bits may evenidentify the offset of a chosen block from the origin. As analternative, the lat/long and extents could be read from aninitialization section, e.g., a map legend, or corner area, etc.

As an alternative, the location information may include an index oridentifier, which is used to interrogate a database to find physicalcoordinates or location information. Upon extraction by a watermarkdecoder, the index is provided to a database. The decoder maycommunicate with a database via a network (e.g., wireless network, LAN,WAN, the internet, intranet, etc.). Alternatively, the database may bemaintained locally, or stored on a computer readable medium such as acompact disk (CD), magnetic tape, magnetic storage device (disk drive,removable media, floppy disks, etc.), electronic memory circuits, etc.Related information that is stored in the database is indexed via thewatermark index.

A grid (or orientation) signal can also be included in the watermarkand/or location information. Preferably, the entire map uses the samegrid signal, so that all blocks in a map can be used to determinedrotation and scale of the map. Such a grid signal may assist indetecting watermarks. (Alternatively, such a grid signal can be used tohelp orient a map. For example, an orientation signal may be used todesignate magnetic North, or another map orientation. Feedback can besupplied to a reader (e.g., watermark decoder) to help orient awatermark reader with respect to a map and the physical surroundingarea. As discussed below, a watermark reader may be provided withcompass-like functionality to assist with such orientation.).

The watermark may be embedded such that it conveys both orientation andmessage information. For example, the modifications made to encodemessage symbols may be made in a manner that creates a recognizablepattern, such as a known array of peaks in a particular transformdomain, such as the autocorrelation domain, the Fourier domain, or someother transform domain. One approach is to embed the message symbols bymodulating a carrier signal with autocorrelation properties that formpeaks in the autocorrelation domain. In particular, by performing anautocorrelation of an image captured of the watermarked map, thewatermark detector generates peaks that can be compared with an expectedpattern of peaks attributable to the carrier signal. The detector thenperforms pattern matching with the peaks to determine the scale androtation of the captured image relative to the watermarked map. Anotherapproach is to use peaks in a particular transform domain (such as theFourier domain) for both orientation and message information. In thisapproach, the watermark is represented as collection of N possible peaksat particular locations in the Fourier magnitude domain. The detectorfirst identifies some subset of the N peaks to determine orientation,and then determines message information by identifying the presence orabsence of peaks at predetermined locations.

In one embodiment, each block on a map has a similar payload structure,e.g., each including the same grid signal and perhaps the coverage areaof the map (e.g., latitude/longitude, range of coordinates, etc., of themap.). The remaining payload bits would then be used to identify theindividual areas (e.g., blocks A-P) on a map 10.

Phase-correlation can be employed to even further improve the locationresolution within a map block. Once the detector has determined therotation and scale of the captured image relative to the watermarkedmap, it can realign the captured image using these rotation and scaleparameters. The watermarked block locations can then be detected byusing the known phase attributes of the watermark signal and correlatingthese known attributes with the realigned, captured image. These blocklocations then serve as reference points for decoding watermark messagedata from a particular block. Also, in one embodiment, resolution downto a pixel within a block is achieved once rotation and scale areresolved.

Watermark Reading Device

A watermark reading device can take various forms. Preferable among suchforms is a handheld reading device 20. (With reference to FIG. 2, ahand-held device 20 may allow better placement of the device in closeproximity to map 10, or sections of map 10 itself, permitting precisionnavigation. A hand-held reading device 20 is typically portable—anadvantageous feature for outdoor and wilderness applications.). Examplesof such hand-held device 20 include stand alone hardware implantations,portable computing devices, personal digital assistants (PDAs), portabledevices such as those manufactured by Compaq (e.g., the iPac line) andHandspring, cellular and satellite phones, smart pens and watches, etc.

A handheld reading device 20 preferably includes a general purpose ordedicated computer, incorporating electronic processing circuitry (e.g.,a CPU) 22, memory 24, an interface 26 to an input device 28, an outputdevice 30 (e.g., a display screen, LED indicators, LED arrows, speakers,and/or audio-synthesis chip, etc.), and optionally a network connection32. (Of course, interface 26 may be integrated with other device 20circuitry, particularly if input device 28 is built onboard device 20.Also device 20 preferably includes sufficient bus or other structure tofacility electronic signal communication between the various devicecomponents, where needed.). The network connection 32 can be used toconnect, through a wireless or satellite connection to a network (e.g.,intranet, internet, LAN, WAN, etc.). In one embodiment the input device(or reading device 20) is tethered to a desktop or laptop computer. Anetwork connection is achieved via the connected computer. Preferably, ahandheld reading device includes (or, alternatively, is in communicationwith) a global positioning system receiver 34. As will be appreciated byone of ordinary skill in the art, suitable software programminginstructions executing via CPU 22 can be used to effect various types offunctionality (including watermark detection and reading) as discussedherein.

The handheld reading device 20 includes (or is in communication with) aninput device 28. The input device 28 may include an optical reader, animaging mouse, a digital camera, a laser or pen scanner, a digital eyemodule, etc. Digital eye modules (such as those provided by LightSurf,Inc.) typically include features such as a complete camera on a chip,CMOS imaging sensor, miniaturized lens and imaging software. Otherimaging devices include a CCD image sensor. Of course, input devices canbe packaged in variety of forms to suit particular applications. (In oneembodiment, an input device 28 is tethered to a personal computer havingwatermark decoding software executing therein.).

The handheld reading device 20 may include additional features toimprove reading and facilitate accurate placement of the device 20 onmap 10. For example, the input device 28 may optionally include atargeting guide, such as a cross-hair-like viewer (or other visualindicator). A targeting guide helps achieve precise placement of theinput device 28 on the map 10. The area within the cross-hairs (ortargeting guide) preferably corresponds with the area captured by theinput device. (Alternatively, the area within the cross-hairs could alsobe a known offset from the area captured by the input device. Watermarkrotation and scale information could be used to determine actuallocation.). In another embodiment, a see-through window is provided tolocate and target an exact map location. (Of course, the input device 28may employ a beam-splitter or reflective lens to ensure that the viewedarea is the same as that captured by the input device 28.). The viewablewindow area corresponds with that captured by the input device 28. Instill another embodiment, a camera-pen or laser-pointer allows a user topin-point a map location, which is scanned (e.g., image capture).

User Applications

A typical application involves a map user placing a handheld readingdevice 20 (or an associated input device 28) near or on a map 10 (FIG.3). (Of course, FIG. 3 is not intended to limit the size relationshipbetween the map 10 and device 20). The input device 28 reads a map area(e.g., area O, or a sub-area within area O), which preferably includesan embedded watermark. The input device provides an output signal (e.g.,representing the captured map area) to the handheld reading device 20.Decoding software running on the handheld device 20 identifies awatermark (if present) from the signal and extracts the embeddedlocation information from the watermark. In one embodiment, map locationfeedback is presented to the user via the reader device's output (e.g.,an audio signal, a text display). The user is then able to compare themap coordinates to coordinates taken from a GPS receiver.

In the preferred embodiment, the handheld reading device 20 includes (oris in communication with) a GPS receiver 34. Location information isextracted from a watermark (step S1, FIG. 4). The current, physicallocation of the handheld reading device 20 is determined via the GPSreceiver (Step S2). In step 3, the handheld reading device 20 compares(and/or correlates) its physical location to the map location scanned bythe input device 28. (Of course, such correlation may be realized bysoftware computational instructions and/or with database/tablelook-up.). The map user is presented with appropriate correctivefeedback, if needed (Step S4). For example, in one embodiment, thehandheld reading device 20 may prompt the user to move the input device28 (or reading device 20) to a map location, which corresponds with theactual physical location of the handheld reading device 20. (In oneembodiment, the prompting is by a visual indicator (e.g., arrows orLEDs) indicating the direction in which the device must be moved. Inanother embodiment, an audio indication is presented, for example, suchas “move six inches to the left and one inch down,” or “move to gridnumber E8.” In still another embodiment, a display screen displays adigitized replica of the map, or a portion of the map, and displays boththe current physical location and the map location scanned by the inputdevice. In still another embodiment, the output device indicates whenthe input device is properly located on the map with respect to theuser's current physical location.).

In another embodiment, the watermark's encoded data includesidentification of a map's grid system. The reading device 20 correlates(e.g., via formula or table/database look-up) the grid system to the GPScoordinate system and conveys to a user her current map grid location(e.g., tells her that she is currently located in grid F-9).

Consider the following examples to even further illustrate the manypossible applications.

A map user is examining a map of the Western United States of Americawhile personally (e.g., physically) being located in Boise, Id. The mapuser places the input device 28 so as to scan a location near Tualatin,Oreg. The handheld reading device 20 can convey (e.g., via the outputdevice 30) to the user to move the input device 28 East and South, untilthe input device 28 corresponds with the user's physical location inBoise. (GPS coordinates can help to facilitate such functionality.). Inthis way, the user can identify her present location with respect to themap. Alternatively, as in another embodiment, the output device 30 canindicate that the user must travel West and North to reach the scannedlocation near Tualatin. In still a further alternative, particularly ifan index or code is embedded in the watermark, additional data can beprovided to the user. To illustrate, the index is used to interrogate anetworked (or local) database. Information, e.g., directions, preferredroutes or roads, mileage between the current physical location and thescanned location, dining or tourist information, etc., is provided tothe handheld reading device for presentation to the user.

As a further example, a user is going on a trip and obtains watermarkedmaps (e.g., from a store, service provider, etc.). The maps are indexedby a MAP ID in a database, which can receive current information (e.g.,promotions) from hotels, resorts, restaurants etc. The information canbe downloaded, streamed, or stored in media (e.g., CD-ROM, electronic ormagnetic media, etc.). The database may be maintained by the handheldreading device or may simply be queried via a communication channel. Asthe user travels, she can place her handheld reading device over variousspots on the map to extract corresponding watermarks. The watermarks arethen used to index the database to retrieve the downloaded informationregarding hotels, resorts, etc. Hence, the watermarked map provides theuser with information for places on the map just by passing the handheldreading device 20 over the map. (In contrast, database-linked GPSsystems typically require the user to be in a particular location to getsuch information about that location.). In another example, a userenters (e.g., alphanumerical values via keypad entry or scanning thearea on the watermarked map) a map location of a desired destination.The reading device determines the present location (e.g., via a GPSreceiver) and provides feedback to the user. In one embodiment, thefeedback is a visual indication (e.g., arrows, LEDs, text directions,grid map coordinates, visual display, etc.) of how to move the handhelddevice to locate the destination point, from the current location. Inanother embodiment, the feedback is a print out (or display) of traveldirections (or map grid numbers) from the current location to thescanned, destination location. In another embodiment, the handhelddevice includes a known laser pointer and sensing array. Once thedestination location is selected, the laser pointer points (e.g.,traces) a direction from the current location to the scanned,destination location, based on the positioning of the pointer asdetermined by the sensing array.

Now consider a potential life-saving example in which a hiker becomeslost in the mountains. The hiker presents a watermarked map to herhandheld reading device 20.

The associated input device 28 scans a location on the map. The readingdevice then gives feedback (e.g., audio, visual, text, etc.) to thehiker to reposition the input device 28 (or the reading device 20) onthe map to correspond with her present physical location with respect tothe mountains. The hiker can then immediately identify where she is withrespect to the map. (Of course, the handheld reading device 20 mayinclude compass-like functionality, common in some GPS receivers. Suchfunctionality is helpful to orient a map with respect to physicalsurroundings, e.g., to align the map's N/S reference orientation withthe environmental conditions.).

Embedding Map Boundaries

A watermark may also include (or reference) information regarding themap within which it is embedded. For example, the watermark may includea range (or boundaries) of coordinates, which define the map 10. Thehandheld reading device 20 may then determine (e.g., calculate based onthe GPS coordinates or via a table look-up) if the user's present,GPS-determined location is viewable on the map 10. The user can beprompted by the device 20 to change maps when her present location isnot viewable on the scanned map. In some cases, the handheld readingdevice may prompt (e.g., via an audible signal, text or graphic, etc.)the user to scan a specific map. This functionality is realizedparticularly well with the aid of additional information, such as thatstored in a database. For example an atlas or an interconnected seriesof maps can be stored according to their corresponding coordinates (or arange of coordinates). When the watermark index does not match thepresent physical location (or fails to fall within the boundaries of themap), the user is prompted to select another map. If a particular set ofmaps is pre-programmed, e.g., preloaded onto the device, stored via CD,or via a specific on-line database, an appropriate map ID or map number(or even map name) corresponding to the scanned coordinates can bepresented to the user.

Road Signs and Tourist Information

Street (or road) signs may also be digitally watermarked as discussedabove with respect to objects. Consider the implications of such. Anautomobile is equipped with an watermark decoder (e.g., an input devicesuch as an optical reader, digital camera, laser reader, etc. andwatermark detecting and decoding software). In one embodiment, the inputdevice is configured with magnification enhancements, such as a zoomlens, signal amplifier, etc., to allow capture of road sign images froma far. The captured images (or corresponding signals) are input foranalysis by the decoding software. The watermark payload is used toconvey related information.

For example, a speed limit sign may include a watermark having acorresponding speed message embedded therein. For example, upon decodingthe watermark, the read device 20 signals (or itself enables) an audiomessage to announce the speed limit. To achieve such functionality, thepayload may include an index that is used to retrieve an audio or wavefile. The wave file could be played via a media player (and outputdevice, e.g., car stereo system), or passed through a digital-to-analogconverter and piped through the car's stereo system. Alternatively, thepayload itself may include enough information to be converted into anaudio message.

In another example, the watermark includes an index that is used tointerrogate a database. The database may be stored locally in theautomobile, or may be accessed via a wireless network. A correspondingdata record is found and returned. The returned data record may includea wide variety of information and data. To illustrate, the returninformation may include data about upcoming rest stops, touristattractions, motels (and vacancy in such), speed limits, restaurants,location data, etc. A mobile traveler, upon receipt of such information,may even make a reservation at a motel via a link provided in the returninformation.

Consider also watermarking tourist, restaurant, convenience andregulatory signs. These too can be embedded with plural-bit data. Acompliant reader extracts embedded information to facilitate theretrieval of additional data regarding the sign. (The term “compliant”in this context implies that the device is able to detect and decodewatermarks.). An embedded index or identifier is communicated to adatabase to index related information (e.g., the database may bemaintained in a CD-ROM, electronic or magnetic memory residing locallyin the automobile, or may be an on-line database accessed via a wirelessconnection. In an online database embodiment, a web browser may beinstalled on a compliant device, e.g., a general purpose computer, tohelp handle the transfer of information, e.g., HTML code, wave files,data files, etc.). Upon receipt of the related data, a traveler mayaccess related data such as menus and prices of local restaurants,vacancies, gas prices, hours of operation, directions and maps, localattractions, etc., etc. (The functionality and systems for linking anidentifier to additional data is even further described in assignee'sU.S. patent application Ser. No. 09/571,422, filed May 15, 2000, nowU.S. Pat. No. 6,947,571.).

Signs at (or maps and photographs of) theme parks, sporting stadiums,concert halls, event centers, convention centers, zoos, officebuildings, government buildings, manufacturing plants, universities,shopping malls, parks, schools, museums, etc., etc., may be similarlydigitally watermarked. A handheld reading device may be used tocoordinate a participant's location with respect to a map and to gatherrelated information as discussed above.

CONCLUSION

The foregoing are just exemplary implementations of navigational aidsusing digital watermarking technology. It will be recognized that thereare a great number of variations on these basic themes. The foregoingillustrates but a few applications of the detailed technology. There aremany others.

While this application discusses a handheld reading device, the presentinvention is not so limited. Of course, an input device may be tetheredto a desktop or laptop computer or compliant kiosk. The input device mayalso communicate with the computer via a wireless channel.

To provide a comprehensive disclosure without unduly lengthening thisspecification, the above-mentioned patents and patent applications arehereby incorporated by reference. The particular combinations ofelements and features in the above-detailed embodiments are exemplaryonly; the interchanging and substitution of these teachings with otherteachings in this application and the incorporated-by-referencepatents/applications are also contemplated.

The above-described methods and functionality can be facilitated withcomputer executable software stored on computer readable mediums, suchas electronic memory circuits, RAM, ROM, magnetic media, optical media,removable media, etc. Such software may be stored on a handheld readingdevice.

The section headings in this application (e.g., “Watermark ReadingDevice”) are provided merely for the reader's convenience, and provideno substantive limitations. Of course, the disclosure under one sectionheading may be readily combined with the disclosure in that of anotherheading.

As an alternative, a handheld device (or an input device) may scan a maparea to capture embedded data. The handheld device wirelesslycommunicates the captured data to a networked computer. The computerdecodes the captured data (e.g., data including a watermark). Thecomputer can then access networked information via the decodedwatermark. The data can be wirelessly communicated to the handhelddevice for display or may even be communicated to a separated device fordisplay.

Also, whereas the figures illustrate the map areas asrectangular-shaped, the inventions are not so limited. Indeed, otherarea shapes may be advantageously employed. As a further alternative,individual map locations are watermarked, instead of watermarkingindividual blocks. For example, on a state map, all city locations arewatermarked according to respective locations. In a city, streets andbuilding locations are watermarked. In another example, areascorresponding to roads, streams, attractions can also be watermarked.

In view of the wide variety of embodiments to which the principles andfeatures discussed above can be applied, it should be apparent that thedetailed embodiments are illustrative only and should not be taken aslimiting the scope of the invention. Rather, we claim as our inventionall such modifications as may come within the scope and spirit of thefollowing claims and equivalents thereof.

1. A handheld wireless device comprising: an input for receiving asubset of database information; electronic memory for storing theretrieved subset of database information, the handheld device includingan input device; an optical imaging device for capturing a portion of amap, the portion of the map including at least one steganographicwatermark hidden therein through alterations to data representing theportion, the alterations being generally imperceptible to a humanobserver of the portion of the map, the steganographic watermarkincluding map location information; an electronic processor configuredto: determine which information of the retrieved subset of the databaseinformation corresponds to the map location information; and controlproviding corresponding retrieved subset database information.
 2. Thehandheld device of claim 1 in which the electronic processor isoperating to perform said determine function or said control function.3. A method for use with a handheld wireless device comprising:capturing imagery of a road or informational sign with an imagingdevice, the imaging device providing data representing at least pictureelements of imagery corresponding to the road or information sign;utilizing a multi-purpose electronic processor for extractingidentifying information from the data representing at least pictureelements of imagery corresponding to the road or information sign; andoutputting a response corresponding with the extracted identifyinginformation, the response being associated with the road orinformational sign.
 4. A programmed handheld wireless device storinginstructions in memory, said instructions are executable by saidprogrammed handheld wireless device to perform the acts of claim
 3. 5. Acomputer readable media comprising instructions stored thereon to causea multi-purpose computer processor to perform the acts of claim
 3. 6.The method of claim 3 further comprising interrogating a database withthe extracted identifying information to locate a corresponding web pageaddress.
 7. The method of claim 6 in which the response comprisesdisplaying a web page associated with the web page address.
 8. Themethod of claim 3 further comprising accessing a file associated withthe extracted identifying information, the file including one of audio,video or text data.
 9. The method of claim 8 wherein the responsecomprises rendering the audio, video or text data.
 10. A programmedcomputing device storing instructions in memory, said instructions areexecutable by said programmed computing device to perform the acts ofclaim
 9. 11. The method of claim 3 wherein the multi-purpose electronicprocessor is utilized for extracting identifying information fromdigital watermarking.
 12. A computer readable media comprisinginstructions stored thereon to cause a multi-purpose computer processorto perform the acts of claim
 9. 13. The handheld device of claim 1 inwhich said handheld device comprises a cell phone.
 14. The cell phone ofclaim 13 in which said optical imaging device comprises a digitalcamera.
 15. A handheld wireless apparatus comprising: an optical imagerydevice for capturing imagery of a road or informational sign, theoptical imagery device for providing data representing at least pictureelements of imagery corresponding to the road or information sign; amulti-purpose electronic processor for extracting identifyinginformation from the data representing at least picture elements ofimagery corresponding to the road or information sign; and an output foroutputting a response corresponding with the extracted identifyinginformation, the response being associated with the road orinformational sign.
 16. The handheld device of claim 15 in which theelectronic processor is operating to extract identifying informationfrom the data representing at least picture elements of imagerycorresponding to the road or information sign.
 17. The handheld deviceof claim 15 in which said handheld device comprises a cell phone. 18.The cell phone of claim 17 in which said optical imaging devicecomprises a digital camera.
 19. The handheld device of claim 15 in whichsaid multi-purpose electronic processor is also for interrogating adatabase with extracted identifying information to locate acorresponding web page address.
 20. The handheld device of claim 19 inwhich said output comprises a graphical user interface (GUI) and theresponse comprises displaying a web page associated with the web pageaddress via the GUI.
 21. The handheld device of claim 15 in which saidmulti-purpose electronic processor is also for accessing a fileassociated with the extracted identifying information, the fileincluding one of audio, video or text data, and the response comprisesrendering the audio, video or text data via the output.
 22. The handhelddevice of claim 15 in which said multi-purpose electronic processorextracts identifying information from digital watermarking representedin the data.